This invention relates to motorboat speed retarding devices and more particularly, but not necessarily, to trolling plates.
Prior workers in this art have recognized that in many instances when an extremely slow boat speed is desirable such speed is not attainable with a propeller driven boat at "idle" speed. Moreover, when a gasoline operated motor is operated for prolonged period of time at "idle" speed, it will foul and often stall. To avoid this situation, it is advisable and necessary to occasionally increase the RPM of motor to motor dislodge the builtup carbon which, if performed during a trolling run, is disturbing to the fish and consequently is responsible for the loss of many potential fish catches.
Various devices suggested by past workers in this art have in the main been limited to mechanically operated devices for disposing a trolling plate or the like either in operating position immediately aft of the propeller and transverse to its wash or in an inoperative position out of the way of the propeller's wash. Usually, the trolling plate was hinged for movement between the operative and inoperative positions of the plate, but occasionally the trolling plate was mounted for vertical rectilinear motion between these two positions. Such mechanical devices have been relatively expensive to construct and maintain and contained complicated parts and assemblies, some of which were relatively fragile, which could be easily damaged or otherwise impaired in usage. Regardless of the mounting arrangement considerable effort and time has been required in the past on the part of the boaters or fishermen to vary the positions of the trolling plate within its operating range.
In view of these difficulties and problems, it is apparent that improvements are needed in this art and especially in the direction of simpler, easier to control and more durable types of apparatus.